class Beercalc

# File lib/beercalc.rb, line 53
def self.aau(alpha, weight)
  unless !alpha.is_a?(Numeric) || !weight.is_a?(Numeric)
    aau = alpha * weight
  else
    aau = nil
  end
end

# File lib/beercalc.rb, line 6
def self.abv(og, fg)
  unless og < fg || !og.is_a?(Numeric) || !fg.is_a?(Numeric)
    abv = (og - fg) * 131
  else
    abv = nil
  end
end

# File lib/beercalc.rb, line 18
def self.abw(og, fg)
  unless og < fg || !og.is_a?(Numeric) || !fg.is_a?(Numeric)
    abv = (0.79 * self.abv(og, fg)) / fg
  else
    abv = nil
  end
end

# File lib/beercalc.rb, line 123
def self.attenuation(og, fg)
  unless og < fg || !og.is_a?(Numeric) || !fg.is_a?(Numeric)
    attenuation = (og - fg)/(og - 1)
  else
    attenuation = nil
  end
end

# File lib/beercalc.rb, line 111
def self.calories(og, fg)
  unless og < fg || !og.is_a?(Numeric) || !fg.is_a?(Numeric)
    calories = ((6.9 * self.abw(og,fg)) + 4.0 * (self.realExtract(og,fg) - 0.1)) * fg * 3.55
  else
    calories = nil
  end
end

# File lib/beercalc.rb, line 168
def self.extractAddition(target_gu, total_gu, extractType)
  # Preset values for LME and DME, or account for a custom value
  if extractType == 'LME'
    extract = 38
  elsif extractType == 'DME'
    extract = 45
  elsif extractType.is_a?(Numeric)
    extract = extractType
  end

  unless !target_gu.is_a?(Numeric) || !total_gu.is_a?(Numeric) || !extract.is_a?(Numeric)
    addition = (target_gu - total_gu).to_f / extract
  else
    addition = nil
  end
  return addition  
end

# File lib/beercalc.rb, line 156
def self.finalGravity(g, vol_beg, vol_end)
  unless !g.is_a?(Numeric) || !vol_beg.is_a?(Numeric) || !vol_end.is_a?(Numeric)
    gu = self.totalGravity(g,vol_beg) / vol_end
  else
    gu = nil
  end
end

# File lib/beercalc.rb, line 189
def self.gravityCorrection(temp, g)
  unless !temp.is_a?(Numeric) || !g.is_a?(Numeric)
    correction = ((1.313454 - 0.132674*temp + 2.057793*10**-3*temp**2 - 2.627634*10**-6*temp**3) * 0.001) + g
  else
    correction = nil
  end
end

# File lib/beercalc.rb, line 133
def self.gu(g)
  unless !g.is_a?(Numeric)
    gu = ((g - 1) * 1000).round
  else
    gu = nil
  end 
end

# File lib/beercalc.rb, line 66
def self.ibu(alpha, weight, time, gravity, volume)
  unless volume == 0 || !alpha.is_a?(Numeric) || !weight.is_a?(Numeric) || !time.is_a?(Numeric) || !gravity.is_a?(Numeric) || !volume.is_a?(Numeric)
    ibu = self.aau(alpha, weight) * self.utilization(time, gravity) * 75 / volume
  else
    ibu = nil
  end
end

# File lib/beercalc.rb, line 30
def self.mcu(weight, lovibond, volume)
  unless volume == 0 || !weight.is_a?(Numeric) || !lovibond.is_a?(Numeric) || !volume.is_a?(Numeric)
    mcu = (weight * lovibond) / volume
  else
    mcu = nil
  end
end

# File lib/beercalc.rb, line 87
def self.plato(sGravity)  
  unless !sGravity.is_a?(Numeric) 
    plato = (-463.37) + (668.72 * sGravity) - (205.35 * sGravity**2)
  else
    plato = nil
  end
end

# File lib/beercalc.rb, line 99
def self.realExtract(og, fg)
  unless !og.is_a?(Numeric) || !fg.is_a?(Numeric) || og < fg
    realExtract = (0.1808 * self.plato(og)) + (0.8192 * self.plato(fg))
  else
    realExtract = nil
  end
end

# File lib/beercalc.rb, line 42
def self.srm(weight, lovibond, volume)
  unless !weight.is_a?(Numeric) || !lovibond.is_a?(Numeric) || !volume.is_a?(Numeric)
    srm = 1.4922 * (mcu(weight, lovibond, volume) ** 0.6859)
  else
    srm = nil
  end
end

# File lib/beercalc.rb, line 144
def self.totalGravity(g,v)
  unless !g.is_a?(Numeric) || !v.is_a?(Numeric)
    tg = self.gu(g) * v
  else
    tg = nil
  end
end

# File lib/beercalc.rb, line 77
def self.utilization(time, gravity)
  unless !time.is_a?(Numeric) || !gravity.is_a?(Numeric)
    utilization = (1.65 * 0.000125**(gravity - 1)) * (1 - Math::E**(-0.04 * time)) / 4.15
  else
    utilization = nil
  end
end